High pressure decorative laminates are known. They are generally produced by stacking and curing under heat and pressure a plurality of layers of paper, impregnated with various synthetic thermosetting resins.
As far as the inventors are aware, there are no self-supported paper based decorative high pressure laminate panels which could be used as a heating panel nor are there processes for economically making these products.
An electric heating assembly for use with a source of electrical power and comprising in combination a panel construction including a heat film panel and facing material on at least one side thereof, with means to secure said panels together in laminated relationship, has been described in Canadian Pat. No. 1,096,919 dated March 81, as invented by Bender. The laminates disclosed in the patent, are wood, metal, plastic, plaster board.
Also Canadian Pat. No . 903,818 dated June 1972, as invented by MacGuire, discloses an electric heating panel comprising an electric heating element fixed within a homogeneous unitary body of a thermo-setting resin having an inert filler. Other types which are less relevant to the subject of this invention include Canadian Pat. No. 706,488 as invented by Ford et al; Canadian Pat. No. 970,816 as invented by MacGuire, Canadian Pat. No. 1,136,194 as invented by Harold.
Electric heating devices located between flexible material sheets are also known and have been described by the inventor Paul Eisler, in U.S. Pat. No. 3,522,415 dated Aug. 4, 1970.
The same inventor has also described other systems: --U.S. Pat. No. 3,510,547 dated May 5, 1970 consists in an electric heating element in a mold structure. - U.S. Pat. No. 3,546,432 dated Dec. 8, 1970 is directed to a wall covering material for use in heating space. - U.S. Pat. No. 3,544,762 dated Dec. 1, 1970, is directed to a method of positioning a dispensable electric heating film. U.S. Pat. 3,539,767 dated Nov. 10, 1970, describes a heating film disposed between two layers, one of which is a floor or a wall covering, and the film being bonded to one of the layers and having at least one of the layers composed of a material supplied in roll form.
U.S. Pat. No. 3,721,800 dated Mar. 20, 1978, is directed to a heating film between two layers one of which being a material supplied in roll form.
U.S. Pat. No. 3,567,353 dated Mar. 2, 1971 is directed to walls covered with a detachable material having passages for a heat exchange medium, or incorporating an electric heating film.
U.S. Pat. No. 3,539,768 dated Nov. 10, 1970, discloses a heating film covering a major portion of the walls of a plurality of rooms, the film being spaced from the walls by means of inflatable insulation.
U.S. Pat. No. 3,751,629 Aug. 7, 1978 is directed to a mobile surface heater.
Other known patents which are believed even less relevant, include:
U.S. Pat. No. 3,089,017 dated May 7, 1963; PA1 U.S. Pat. No. 3,897,928 dated Aug. 5, 1975; PA1 U.S. Pat. No. 3,846,204 dated Nov. 5, 1974; PA1 U.S. Pat. No. 3,751,629 dated Aug. 7, 1973.
All these are directed to structures which are either flexible, or are weakened by heating elements or are heavier because of such elements. In other words, products are known where the heating elements impair the structures by rendering them heavier, weaker, or cumbersome or more difficult to manufacture and to handle during shipping.
Also apparently fibreglass has been used to support electrically heated structure. However, such a system is time consuming the fibreglass is added in layers by hand, each layer requiring to be dryed before adding the next one, and also fibreglass is expensive.